1. Field of the Invention
The present invention relates to a stacked solid electrolytic capacitor and a method for manufacturing the same. In particular, the present invention relates to a stacked solid electrolytic capacitor that reduces the positive electrode welding energy to prevent the current leakage from occurring and a method for manufacturing the same.
2. Description of Related Art
Capacitors are popularly used in the consumer household equipments, computer motherboards and the peripherals, power supplies, communication products, and cars. The functions of the capacitors include filtering, bypassing, rectifying, coupling, de-coupling, and phase-converting, etc. It is a key component for electronic devices. Capacitors have different types according materials and functions.
The solid electrolytic capacitor has a lot of merits, including small size, large capacitance, and good frequency characteristic, etc. The solid electrolytic capacitor can be used as a de-coupling function for the power circuit of the central processor. As shown in FIG. 1, the stacked solid electrolytic capacitor of the related art includes a plurality of capacitor units 10b. Each capacitor unit 10b includes a positive electrode portion 11b, a negative electrode portion 12b and an insulating portion 13b. The insulating portion 13b makes the positive electrode portion 11b be electrical insulated from the negative electrode portion 12b. The negative electrode portions 12b of the capacitor unit 10b are stacked. A conductive glue material is located between the capacitor units 10b so that the capacitor units 10b are electrically connected.
The front side of the positive electrode portion 11b of the capacitor unit 10b extends to form a positive electrode pin 14b. The positive electrode pin 14b is bent and is welded with a positive electrode conducting lead frame 20b to be electrically connected. However, when the quantity of the capacitor units become larger and larger, the quantity of the positive electrode pins 14b welded with the positive electrode conducting lead frames 20b also becomes larger so that the required welding energy also increases. High welding energy easily damages the oxidation aluminum dielectric layer (not shown in the figure) located on the surface of the positive electrode portion 11b of the capacitor unit 10b. Thereby, current leakage occurs. Furthermore, when the quantity of the capacitor units 10b is large, the positive electrode pin 14b of the electrode conducting lead frame 20b that is far away from the capacitor unit 10b is largely bent. The large bending size also damages the structure of the positive electrode portion 11b to make current leakage occur. The current leakage reduces the yield rate of the solid electrolytic capacitor. The circuit with the solid electrolytic capacitor also will be short-circuit, and its usage life is reduced.